FPCN39 CWLW 111431
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 7:00 AM PST THURSDAY 11 FEBRUARY 1999 FOR
TODAY.

VENTILATION INDICES (TEMPERATURE) AND MIXING HEIGHTS.
MIXING HEIGHTS IN METRES ABOVE SEA LEVEL.
AVERAGE WINDS IN KNOTS.

SPOT INDICES ARE DETERMINED BY THE ASPECT AND ELEVATION OF THE SITES.
COMPARE WINDS, TEMPERATURES AND ELEVATION WITH THE SITES HERE
TO DETERMINE THE INDEX IN ANY OTHER AREA.

SOUTHERN INTERIOR

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
FRSR CANYN   KEL      21    1     600   3     72    3    1450  15
KAMLOOPS     KEL      22    0     700   4     62    3    1450  10
OKANAGAN     KEL      16   -1     550   3     59    3    1400  10
CASTLEGAR    SPOK     24   -3     800   5     47    0     900   8
CRANBROOK    SPOK      9   -9     950  17     38   -3    1000   8
REVELSTOKE   KEL      18   -1     650   4     30    0    1000   4


*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    S   15   S   41   SW  93
CRANBROOK             SW  20   SW  69

TODAY'S VENTING: GOOD IN THE SOUTHWEST. FAIR IN THE SOUTHEAST.


VENTING FOR FRIDAY: FAIR.


CENTRAL INTERIOR/NORTHEAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
WILLIAMS L   P.G.    100   -3    1700  32    100   -1    2000  35
PR. GEORGE   P.G.     96   -2    1150  35     96   -2    1150  35
SMITHERS     P.G.     71   -2     900  22     71   -2     900  22
WELLS GRAY   P.G.     70   -1    2000  40    100   -1    2000  40
FT NLSN      F.N.      9  -25     400   0     29  -21    600   0
FT STJOHN    F.N.     29  -17     900  10     49  -12     800  11


*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            S   85   SW 126
SMITHERS              S   70   S  126

TODAY'S VENTING: GOOD IN THE CENTRAL INTERIOR. FAIR IN NORTHEASTERN
B.C.


VENTING FOR FRIDAY: FAIR


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     90    6     500  35    100    8    1050  43
FRASER VLY   QUIL      9    3      50  22     84    6     400  35
SRN VRISL    QUIL     41    6     250  16    100    8     900  35
CNTRL VRISL  QUIL      9    5      50   9    100    7     700  32
NRN VRISL    HRDY     40    3     300  20    100    7     800  30
TERRACE      ANT       9   -1     200  41     40    0     200  41
STEWART      ANT      10   -1     200  25     30    0       0  25


*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    S   72   S  104   SW 120
PORT HARDY   S  104   S  126   SW 124
SANDSPIT     S   43   S   61   S   78

TODAY'S VENTING: GOOD EXCEPT FAIR IN INLAND AREAS OF THE NORTH
COAST.


VENTING FOR FRIDAY: FAIR


VENTILATION GUIDELINES:
          0-33.....POOR
          34-54.....FAIR
          55-100.....GOOD.
VENTILATION INDICES NORMALLY DROP TO POOR AFTER SUNSET.


END/GF